[Predictors of Hematologic Responses in Patients with Non-Transfusion-Dependent β-Thalassemia Receiving Thalidomide Therapy].

Objective: To explore the predictors of hematologic responses of non-transfusion-dependent β-thalassemia (NTDT) to thalidomide.

Methods: 33 patients with NTDT who treated with thalidomide in the 923rd Hospital of the Joint Logistics Support Force of the People's Liberation Army from May 2016 to June 2019 were included in the study. The basic data, hematological indexes, degree of treatment response and genetic background of the patients were analyzed.

Results: The baseline fetal hemoglobin (HbF) level of main responders (MaR) was significantly higher than that of minor responders (MiR) and no responders (NR) (P=0.001). And the baseline HbF level was positively correlated with hemoglobin increment after treatment (r=0.601). Genetic background analysis showed that the frequencies of the genotype CT of HBG2 rs7482144 (P=0.031), the genotypes CT/CC (P=0.030) and the minor allele C (P=0.015) of HBS1L-MYB rs9399137, the genotypes AT/TT (P=0.030) and the minor allele T (P=0.028) of HBS1L-MYB rs4895440, the genotypes AG/GG (P=0.030) and the minor allele G (P=0.028) of HBS1L-MYB rs4895441 (P=0.030) in MaR group were significantly higher than those in MiR and NR groups. Comparing the area under the ROC curve (AUC) of the above indicators to predict the main response, the results demonstrated that the predictive value of baseline HbF level was significantly better than rs7482144 (0.91 vs 0.72, P=0.003), rs9399137 (0.91 vs 0.74, P=0.022), rs4895440 (0.91 vs 0.74, P=0.023) and rs4895441 (0.91 vs 0.74, P=0.023), but there was no significant difference in the predictive value between combined single nucleotide polymorphisms (SNPs) (0.91 vs 0.88, P=0.658）and baseline HbF combined SNPs (0.91 vs 0.97, P=0.132). The AUC value of baseline HbF predicting the efficacy of thalidomide as the main response was 0.91, the cut-off value was 27.4%, the sensitivity was 100%, and the specificity was 58.3% (P=0.001).

Conclusion: The hematologic response of NTDT to thalidomide is variable and complex. Compared to genetic background, baseline HbF may be a simpler and more efficient tool to predict efficacy response.